Changing the Differential Fluid

[IMPRMNS]

I've never done changed diff fluid before so I am going to put my pride in the backseat and just ask. Are these these the drain/fill ports?

From a process standpoint, my understanding is that this is pretty simple.

1) Start with a warm axle
2) Remove fill plug
3) Remove drain plug & drain
4) Replace drain plug; torque to 31Nm
5) Fill with SAE 80w90; 2.1L for both front and back
6) Replace fill plug; toque to 31Nm

Am I missing anything?

 

[Clark Kent]

I've never done changed diff fluid before so I am going to put my pride in the backseat and just ask. Are these these the drain/fill ports?

From a process standpoint, my understanding is that this is pretty simple.

1) Start with a warm axle
2) Remove fill plug
3) Remove drain plug & drain
4) Replace drain plug; torque to 31Nm
5) Fill with SAE 80w90; 2.1L for both front and back
6) Replace fill plug; toque to 31Nm

Am I missing anything?

Yes they are the drain and fill ports.

7) Check all plugs for leaks after the first drive.

 

[ECrider]

I've never done changed diff fluid before so I am going to put my pride in the backseat and just ask. Are these these the drain/fill ports?

From a process standpoint, my understanding is that this is pretty simple.

1) Start with a warm axle
2) Remove fill plug
3) Remove drain plug & drain
4) Replace drain plug; torque to 31Nm
5) Fill with SAE 80w90; 2.1L for both front and back
6) Replace fill plug; toque to 31Nm

Am I missing anything?

Your front diff fillet has much better access than mine - right hand drive here

Thinking that next time I need fill mine then will jack the body up as best I can which gives a much better angle of attack with a ratchet

 

[IMPRMNS]

Another newbie question…can one overfill an axle? My differentials took more than the cited 2.1L of 80w-90 when filling to the level of the fill hole.

 

[255/85]

You'll know if it starts burping out of the breather tube.

In all seriousness, overfilling can lead to air entrainment in the fluid - otherwise known as frothing. Reduced lubrication is the result. You should be fine at the top of the fill hole.

 

[ECrider]

If you still have the one way valve OEM breather and it is clear of crap and working properly then should expel any over fill.

I reckon the diff takes a good 2.5l upto the filler.

I don't think this is a bad amount.

I do however think the OWM breather is flawed and best replaced with a neutral pipe arrangement.

 

[JKAlpine]

What size the the plug? Is it hex or torq?

 

[CountyV8]

It is NOT fill to spill check it needs to be filled bellow the spill level.

Post in thread 'Diff oil level measuring tool?'

Mar 3, 2025

Why do you want to buy such a tool? Make one.! All you need is a wire hook with a leg length of approx. 35 mm on the short side. If you then fill the differential with exactly 2.1 liters of oil, the oil level will be approx. 23 mm below the filler opening. You can always check the oil level using a corresponding mark on the hook mentioned above. However, unless you do have an oil loss in the differential area, there will hardly be any reason to check the oil level. Given the price of the differential oil (approx. 5 euros per liter), it should be much easier to simply change the oil every...

• Greasemonkey

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[abbeyroad]

Has anyone sourced a front and rear diff fluid change kit with INEOS factory parts? Typically, they require a least a crush washer of some type. I know my Raptor actually treats the plug itself as one time use.

 

[C-Mack]

I use finely graduated plastic containers (like a 1 gal. clear painters bucket with metric and standard measurement marks) to routinely drain the oil from the diffs/transfer boxes on all my vehicles to see what actually drains out and compare it to the specified amount in the manual to see if any has leaked. More often than not the amount drained closely matches what is in the manual and I make sure to put the specified amount back in with a hand operated fluid pump.

Never had an issue using this method but one very important key is to make sure the vehicle is perfectly level front to back and side to side before starting. It seems a lot of modern vehicles don’t use the fill hole level method and instead specify the exact amount to put in. Also lifted vehicles where the axle diffs have rotated slightly will give you different readings or in some cases lower the fill hole low enough you can’t get the correct amount back in without jacking the axle up a bit so it pays to be precise.